This invention relates to a slider reciprocating driving apparatus for reciprocating a slider having a contact glass thereon for use in an electrophotographic copying machine, and more particularly to a slider reciprocating driving apparatus including a rotation control member which is rotated intermittently in association with the driving mechanism for reciprocating the slider, and in which the intermittent rotation of the rotation control member controls a sequence of a copying process of the copying machine and in which the slider can be reciprocated freely when the copying machine is not in operation.
In an electrophotographic copying machine of the type whose contact glass is movable, a slider supporting the contact glass thereon is reciprocated by a predetermined stroke in accordance with the rotation of a photoconductor drum for forming a latent electrostatic image corresponding to an image of an original document to be copied on the photoconductor drum during the forward movement of the slider.
In the field of this technique, various driving mechanism for reciprocating the slider have been proposed. In one example of the reciprocating mechanism, a pulley around which a wire for directly driving the slider is wound, and a magnetic clutch disposed in a driving mechanism for driving the pulley are employed so as to reciprocate the pulley, by energizing and deenergizing the magnetic clutch. Such a slider driving method, however, has some shortcomings. For example, the magnetic clutch itself is expensive and its torque is varied by variation of an input voltage to the magnetic clutch, and some slipping occurs in the magnetic clutch due to foreign material entering a brake portion of the magnetic clutch.
In contrast with this, a slider driving apparatus which is operated by mechanical means only, without employing the above-mentioned magnetic clutch, has been proposed by the inventors of the present invention (refer to Japanese Patent Application No. 33766/1976). In this driving apparatus, a wire is wound around the peripheral surface of a wire drum and one end of the wire is connected to the leading end of a slider and the other end of the wire is connected to the rear end of the slider so that the wire drum is rotated in the forward and the backward direction, and the switching between the forward and backward rotations is effected by a mechanical clutch.
As is well known, the copying process of an electrophotographic copying machine comprises various steps such as charging, exposure, development and paper feed. These steps are followed in accurately timed relation. For example, a paper feed apparatus has to be operated properly in order to feed a transfer sheet to a transfer station. A control of such a step could be made easily by use of a timer. However, an appropriate electric control circuit is required.
From this point, it would be useful to provide a process control mechanism for effecting the above-mentioned sequence control, and to incorporate the process control mechanism in the above-mentioned purely mechanical slider driving apparatus in such a manner as to operate the process control mechanism associated with the driving mechanism, since such an electrical control circuit and a timer, as mentioned above, are unnecessary and the driving system can be simplified.
In the above-mentioned slider driving apparatus, when the copying machine is not in operation, the slider cannot be reciprocated freely. Therefore, it is difficult to adjust the timing of each element of the copying machine at the time of assembling, inspection and maintenance of the copying machine. Furthermore, when a paper jam occurs during the operation of the copying machine, it is difficult to remove jammed paper.